CAIRO — Dozens of suspected militants openly joined a mass funeral procession Saturday for four slain Egyptian insurgents killed in an Israeli drone strike in the Sinai Peninsula, as Egyptian security forces watched them pass by.

A little known militant group, Ansar Jerusalem, said its men were the target of the drone strike in Egyptian territory that killed the four militants preparing to fire rockets into Israel. Meanwhile, Egypt’s military claimed that one of its helicopters carried out the strike, seeking to limit public criticism about allowing Israel to carry out strikes on its soil.

By nightfall, security officials told The Associated Press that two Egyptian helicopters fired at a gathering of militants near the desert town of Sheik Zuweyid in the northern part of the peninsula. The officials, who spoke on condition of anonymity because they were not authorized to release the information, said that four militants were killed and at least seven wounded.

The AP could not immediately reach area residents because it appeared that mobile phone service was disrupted temporarily, a security tactic used in past military operations in Sinai.

The attack a day earlier by the Israeli drone was a rare operation that could indicate increased cooperation between Egypt and Israel against militants in northern Sinai after a coup ousted Islamist President Mohammed Morsi last month. It also is likely to increase tensions in a border region that has seen other rocket attacks in the past.

Hundreds of people, including armed jihadis, tribesmen carrying weapons and family members of the dead took part in the funeral. The bodies of the dead were displayed in the back of pickup trucks draped by black flags inscribed with Islamic verses. The flags are often used by al-Qaida militants, but also by Islamists. Some in the procession chanted slogans against Israel and Egypt’s army.

The procession passed through checkpoints peacefully, even though many who were present likely are the same fighters carrying out near-daily attacks on security forces in Sinai. Security officials said the nature of the attack made it difficult to stop the procession out for fear of inflaming an already volatile situation. They also said checkpoints in the area were manned by just a handful of personnel ill-equipped to take on such a large group, which also included a number of locals.

In its statement, Ansar Jerusalem denounced the Egyptian military for having allowed the Israeli attack.

“What is greater treason than the Egyptian army allowing the Zionist drones to violate Egyptian airspace now and then?” it said.

The statement’s authenticity could not be confirmed, but it was posted on a website commonly used by militant groups.